High-voltage power supply



mm raw-wwmmm Jan. 18, 1949.

G. w. FYLER 2,

HIGH VOLTAGE POWER SUPPLY Filed April 7, 1948 r 3: 40 cc H II f L42 l L46 MU U L JNVENTOR.

George W. Fyler f wkyxmzv Afly.

Patented Jan. 18, i949 U UNITJEDT 's'TATEs PATENT T'OFFICE HIGH-VOLTAGE POWER SUPPLY 1 George W. Fyler, Lombard, ILL, assignor to Motorola, Inc., Chicago, 111., a corporation of Illinois v I fl 7 Application April 7, 1948, Serial No. 19,482

2 Claims. (Cl. 250-36) a 1 a 2 This invention relates to high-voltage power excitation voltage. Capacitive feed-back takes supplies for'use in television-systems and the like. place between the rectifier anode and the coil Cathode ray tubes employed in television sets spring to sustain oscillations in the oscillator require extremely high direct-current voltages circuit.

for their operation. A common type of high- 5 Referring now to Fig. 1, the radio-frequency voltage power supply for such tubes utilizes a oscillator includes a triode having an anode l2 radio-frequency oscillator, a transformer and a which is connected to the intermediate tap it of rectifier. The radio-frequency output of the an auto-transformer IE. The anode supply voltcillator is stepped up by the transformer and apage for the tube [0 is furnished through a radioplied to the rectifier, which converts this output frequency choke l8 and the coil of the transto direct current. In order to sustain oscillations, former Hi to the anode [2. The tank circuit l9 there must be a feed-back from the secondary of the oscillator is formed by the coil 20 in parside of the transformer to the control element or allel with a capacitor 22 which resonates with the grid of the oscillator. Customarily this feedcoil 20 at a predetermined radio-frequency. This back has been provided by means of a tickler tankcircuit is roughly tuned to the natural frewinding or turn on the transformer. Consideraquency of the transformer secondary, which comble difliculty has been experienced with these prises the coils 20 and 24 in series. This arrangetickler arrangements due to the severe insulation ment generates a high voltage of, say, 6,000 peak requirements and the construction problems volts in the transformer secondary.

involved. The high radio-frequency voltage is applied to An object of the present invention is to provide the anode 26 of a diode rectifier 28. The cathode an improved feed-back device for high-voltage 30 of the rectifier 28 is connected through a filter power supplies which replaces the conventional capacitor 32 to ground. The radio-frequency ostickler, M cillations are rectified by the diode 2B and filtered Another object is to utilize a novel form of ca- L bythe capacitor 32 (together with any other filter pacitive coupling for the feed-back. elements that may be employed in the circuit) to Still another object is to mount the feed-back furnish the direct-current output voltage of the element directly on the rectifier tube. power supply.

A feature of the invention is the provision of For sustaining oscillations, the control grid 34 a feed-back element in the form of a coil spring 30 of the oscillator tube 10 must be supplied with disposed around the envelope of the rectifier. radio-frequency voltage of approximately the 21 There is suflicient capacitive coupling between correct amplitude in proper phase relation to the this coil spring and the rectifier anode at radio oscillations in the tank circuit l9 to maintain frequency to effect the necessary feed-back to the these oscillations. The feed-back required for oscillator. This arrangement does not require a 35 this purpose can be obtained by means of a caspecially built rectifier tube, as it can readily be pacitive coupling with the anode 26 of the rectiapplied to conventional tubes. fier 28. In accordance with the invention, a coil The foregoing and other objects, features and spring (fragmentarily represented in Fig. l and advantages of the invention will be better undershown more fully in Fig. 2) is carefully mounted St y reference o h fo l wing description 40 on the envelope of the tube 28. A strip of tape taken in connection with the accompanying draw-- 42 is placed around the tube envelope in the apwherein: proximate correct location, and the spring 40 is Fig. 1 is a schematic diagram of a high-voltage placed over this tape and cemented in place. The

power supply constructed in accordance with and tape 42 serves to locate th spring 40 p p embodying the principles of the invention; and 4 keeps the spring in its proper position, and in- Fig. 2 is an elevational view of a rectifier tube creases the insulation. The cement prevents equipped with a feed-back element as described corona. above. The tube 28 represented in Fig. 2 is a typical In practicing the invention, the output of a diode structure (type 1B3GT, for example) which radio-frequency oscillator is fed through an auto- .30 may be utilized, but the invention is not, of transformer toadiode. Acoil springis positioned course, limited to this particular form of tube. on t pe of the diode so as to have the de- The tube electrodes are concentric, the anode 5 sired capacitive coupling with the anode of the constituting the outer electrode. Before being tube, and this spring is connected to the control cemented in place, the spring 40 may be adjusted grid of the oscillator tube to provide correct grid up or down for positioning relative to the electrostatic field of the tube so as to provide optimum grid excitation voltage. The adjustable capacity between the anode 26 and spring 40, in series with the fixed input impedance of the tube l0, constitutes a voltage divider for this purpose. A range of 2/1 is easily obtained.

The anode 26 is electrically connected to a cap 44 on the topsofthe tube. 28, tcrwhicln theleadi.

from the transformer lB-is connected byazsuitable clip (not shown). The tube base 46 is provided with the usual centering post 48 and prongs- 50. The tube envelope 28 may be ofglassor other.

suitable material which does not form an electrostatic shield about the anode 2Bi. The: glass;

envelope serves as an insulator-and provides good surface creepage insulation even under high humidity conditions.

The control grid 34 of the oscillator tube I is connected to ground through a grid leak resis'-- tor 52 having a high resistance. The cathode 54 of; tube: HIE is". connected. through the: parallelfi combination. of a. bias resistor 56 and; bypass.

capacitor: 585 to ground; Aibypass capacitor: 60: connects the low-voltage end of the tank l3: tmgitound... The. valuesmf theevaricus: circuit components. are chosen. to: provide: the.- desired i'adicdrequency; which may, be. cm the. order? of; 1-101 lrilocycles;-

The; above described. arrangement dispenses; withthe: troublesome tickler-ror: feed-backtinductz-- 3.-I1C6:\Vhi0hlh8i$ been employed: inipower. supplies: oftthis kind. prion to' thepresent. invention. The: coil" spring: 4011s very: convenient.- to. use by, com;- parison with. the conventionali ticklers, and. thehigh voltage performance is more uniform and? reliable in manufactured. sets. using; this. device.

While a preferred embodiment of;the: invention has beendisclosed; thissobviously candle. modified: without departing: frorrn the principles stated above;v and: it. is; intended: thatv the appended claims shall .cover all such modifications.

I claim:

11 In. a high voltage; direct; current power: sup:- ply'system, the combination includinganoscilla-m tor: circuit: providing; an oscillatory voltage;v an; inductance having: two; portions with. one portion. electrically connected intd saids oscillator cir-- cuit, a rectifier tube having a cylindrical insulateing envelope and concentric rectifying; elements Within said envelope; said: rectifying. elements including: an inner. cathode: and anouter. tubular. anode; said inductance: portions being. 50- conproviding the voltage required for the anode of .znoathoderay tube,. the combination including an oscillator. circuiizprnviding an oscillatory voltage, an auto-transformer having two portions with onaportion. electrically connected into said oscillator circuit, a rectifier tube having a cylindrical glassenvelope and concentric rectifying elements within said envelope, said rectifying elements includingv an". inner cathode:- and an outer. tubular anode-spaced fr0m=said.glassenvelope said.auto.- transfcnner.- portions being so.- connected; and phased that. saidv oscillatory voltage; stepped up: therein, said. anode. being connected tosaid autoftinnsformer atthehi hvoltagepoint thereon for. providing annidirecticnalvoltage.output. and means for providing energy feed b'acli to said oscillator. circuit comprising. an electrically conductive: tension. coiled spring. lust'ably mounted;on.the.outside.oifsaid glass envelope and? capauitlvely coupledi'to, said tubular anode, said.

springibeingelectrically connected to said oscil1a.- tor. circuit andprnvidlhg feedback therefor.

GEORGEW. FYILER'.

REFERENCES CITED- The following; references: are; of. recordin. the

file of this patent; I

UNITED STATES PATENTS I Date.

Sziklai Jan. '1, 194.1" 

